Apparatus and Method for Gripping and/or Handling Tubulars

ABSTRACT

Gripping tool ( 10 ) and method to assemble tubular strings comprising a shaft ( 51 ) having first and second externally and oppositely threaded portions ( 52, 54 )); and first and second generally frusto-conical cams ( 32, 34 ) threadably received on the first and second threaded portions. Cams ( 32, 34 ) adduct and abduct upon rotation of the shaft ( 51 ) in the first and second directions, respectively. Tool can comprise a plurality of jaws ( 42, 44 ) disposed within the variable space intermediate the cams ( 32, 34 ). Jaws ( 42, 44 ) cam radially outwardly upon adduction of cams ( 32, 34 ) to grip the wall of a tubular ( 90 ), and jaws ( 42, 44 ) can retract radially inwardly upon abduction of the cams ( 32, 34 ) to release. Tool ( 10 ) may comprise a shaft ( 101 ) having a bore ( 152 ) to facilitate fluid flow into tubular ( 118 ), and may cooperate with a fill-up and circulation tool and/or a cementing assembly.

FIELD OF THE INVENTION

The present invention relates to an apparatus and method to grip and/or handle tubular segments, such as tubulars used for forming tubular strings that are used for lining earthen boreholes drilled for oil and gas recovery. The present invention specifically relates to a method and apparatus to assemble tubular strings and/or install them in a borehole, and to disassemble tubular strings.

BACKGROUND OF THE INVENTION

Tubular strings are critical components in the drilling and completion of wells used for oil and gas recovery from mineral deposits within geologic formations in the earth's crust. Tubular joints, also called tubular segments, are generally joined together using threaded connections to form tubular strings. Tubular strings may be used to line an earthen borehole to prevent collapse of the borehole and/or as a fluid conduit to produce fluid from a geologic formation.

The assembly of a tubular string involves repetitive handling of tubular segments. A tubular segment is secured to a hoist and lifted above the earthen borehole containing the tubular string. An add-on tubular segment is generally positioned over well-center so that the externally-threaded pin end of the lower end of the add-on tubular segment is received within the internally-threaded box end of the previous tubular segment that was added to the tubular string. A power tong may be used to grip and rotate the add-on tubular segment to make up the threaded connection comprising the pin and box ends of the abutting tubular segments. For example, where the “box end up” method is used, when the connection is made up and torqued to the appropriate tightness, the tubular string may be released from the power tong and an elevator may grip the box end of the newly added tubular segment to suspend the tubular string within the borehole and unload a spider that suspends the tubular string in the borehole. Once the spider is disengaged, the elevator may be lowered to dispose the lengthened tubular string deeper into the borehole until the box end of the newly added tubular segment is positioned above the spider for receiving the next add-on tubular segment to be made-up into the tubular string. The newly added tubular segment is gripped by a spider at or above the rig floor so that the box end connection is presented just above the rig floor and ready to receive and couple to a new add-on tubular joint. The elevator is released from the tubular string and the next add-on tubular segment is positioned for being threadably connected into the tubular string. This cycle is repeated until the tubular string achieves the desired length. The lifting, positioning, aligning and/or rotating of a tubular segment to make-up the threaded connection to a tubular string can be referred to as “handling” or “manipulating” the tubular segment.

Various casing running tools have been proposed for use on rigs equipped with top drive assemblies. Top drive assemblies typically comprise rail-mounted motors powering a downwardly disposed and rotatable drive shaft for rotating a pipe or a pipe string. Casing running tools adapted for use with top drives are typically connected to the powered drive shaft so that the top drive can be used to rotate casing segments to make-up threaded connections. A casing running tool for use with a top drive assembly may comprise an internally gripping assembly receivable in the presented end of a casing segment. Casing segments may be lifted onto the rig floor using a single joint elevator or other hoisting device, then the top drive assembly is typically used to manipulate the casing running tool to couple the new segment to the string in the borehole.

During the process of making up and running tubular segments, fluid can be added to the bore of the tubular string to prevent excessive differential pressure from damaging or collapsing the tubular string. The addition of predetermined amounts of fluid into the end of the tubular string accessible to the rig can balance the hydrostatic pressure in the bore of the tubular string with the hydrostatic pressure in the annulus between the tubular string and the borehole wall or, if the borehole is cased, between the tubular string and the casing.

There is a need for an apparatus for gripping and handling tubular segments on a rig which can either be used with a top drive or as a stand-alone tool on a conventional rig that is not equipped with a top drive. The apparatus may be compatible for use with fill-up and circulating tools, cementing heads, wiper plug assemblies, and other devices for delivering and circulating mud and other fluids, such as a cement slurry. A need exists for an apparatus for joining tubular segments to a tubular string that requires no external drive for powering and operating the tool. There is a need for an apparatus for gripping a tubular segment that will not loosen its grip on a tubular segment upon loss of power to operate the gripping assembly of the apparatus. There is a need for an apparatus that uses mechanical advantage to grip a tubular segment with minimal mechanical power requirement compared to conventional, asymmetrically deployed gripping devices. There is a need for an apparatus for gripping a pipe segment that does not cause excessive marking of the gripped surface of the pipe segment. There is a need for an apparatus that uses sufficiently small amount of mechanical power so that a portable energy source, such as a battery, may be used to power the gripping assembly into and out of gripping engagement with the tubular segment. There is a need for an apparatus for gripping a tubular segment that is adapted for use with a fill-up and circulation assembly for introducing and circulating fluid in a borehole.

SUMMARY OF THE INVENTION

At least one embodiment of the present invention provides an apparatus and method that satisfies some or all of the aforementioned needs, and others. An embodiment of the apparatus can internally grip a tubular segment for coupling the tubular segment to a tubular string in a borehole. The apparatus can be self-operable for gripping and releasing, and in one embodiment does not require the apparatus be attached to, supported by or driven by a top drive assembly. In addition to being suitable for use with a top drive, an apparatus may be used as a stand alone tool, e.g., an apparatus that may be suspended from the traveling block of a conventional rotary rig. An apparatus may be used as a single joint elevator and a method of the present invention may be used for making up or running tubular strings into a borehole and/or breaking out or removing tubular strings from a borehole, or any combination thereof. An apparatus and method may be used with conventional tools for introducing fluid into a tubular string and for circulating fluid within a borehole. Moreover, an embodiment can provide the consistent application of sufficient gripping force to lift and/or threadably couple a tubular segment to a tubular string without the use of hydraulic cylinders to power the gripping jaws into engagement with the tubular segment being lifted and/or coupled.

In one embodiment, there is provided an apparatus for gripping and handling tubulars compromising a drive shaft, at least one drive motor for rotating the drive shaft, a first camming body threadably received on a first threaded portion of the drive shaft, a second camming body threadably received on a second portion of the drive shaft, and a plurality of gripping jaws slidably disposed within a jaw space between the first and second camming bodies. The gripping jaws are positioned about the drive shaft such that the first and second camming bodies threadably adduct generally longitudinally along the drive shaft one toward the other when the drive shaft rotates in a first direction, and abduct generally longitudinally along the drive shaft one away from the other when the drive shaft rotates in the reverse direction.

The gripping jaws are slidably engaged by the first and second camming bodies such that, when the drive shaft rotates in the first direction, the first and the second camming bodies adduct to slidably and evenly displace the gripping jaws from the jaw space and radially outwardly away from the drive shaft to bear against the interior wall of a tubular segment into which the apparatus is received. The gripping jaws are radially outwardly displaced to engage the internal wall of the tubular segment with an amount of gripping force sufficient for lifting and coupling the tubular segment to the tubular string. The adduction of the camming bodies, one toward the other with generally synchronous movement, provide an even application of force to the gripping jaws as they engage and grip the interior wall of a tubular segment. This even application of force across the gripping jaws may provide minimal marking of the interior wall of the tubular.

In another aspect, the drive shaft of the gripping apparatus may comprise an axially extending bore there through to allow pressurized fluid to be delivered from the rig, through the bore of the drive shaft, and into the bore of the tubular segment to be gripped and rotated by the gripping apparatus. In another aspect, the gripping apparatus may comprise a fill-up and circulation assembly extending from the distal end of the drive shaft and into the bore of the tubular segment gripped by the gripping apparatus.

In another aspect, there is provided an apparatus for handling tubulars comprising a gripping apparatus including a drive shaft having an axial bore there through, a drive motor for rotating the drive shaft, a first internally-threaded camming body threadably received onto a first externally-threaded portion of the drive shaft, and a second internally-threaded camming body threadably received onto a second externally-threaded portion of the drive shaft, such that the first and the second camming bodies are threadably adducted along the drive shaft one toward the other to narrow a jaw space when the drive shaft rotates in a first direction and abducted one away from the other to widen the jaw space when the drive shaft rotates in the reverse direction, and a plurality of gripping jaws slidably engaged and displaced from the jaw space radially outwardly away from the drive shaft by the first and the second camming bodies when the drive shaft rotates in the first direction and allowed to retract radially inwardly into the jaw space toward the drive shaft when the drive shaft rotates in the reverse direction.

The apparatus may further comprise an apparatus adapted for being suspended from and supported by a pair of elongate bails. The bails each have an upper and a lower connection, the upper connection adapted for being coupled to the traveling block of a conventional rig and the lower connection for coupling to the gripping apparatus of the present invention. This embodiment may be adapted for receiving at least a portion of a fill-up and circulation assembly within the bore of the drive shaft. Specifically, this alternate embodiment may be adapted for receiving a hollow tubular member having an external elastomeric seal within the bore of the externally-threaded drive shaft for creating a seal between the discharge of a fluid pump on or near the rig and the internal wall of the tubular segment gripped by the gripping apparatus. The fill-up and circulation assembly may be suspended from the traveling block and positioned between the bails, and the fill-up and circulation assembly may be adapted for being extendible and retractable for selectively inserting and removing the lower end of the fill-up and circulation assembly from the bore extending longitudinally through the rotatable drive shaft of the gripping apparatus.

In another aspect, there is provided a method of coupling tubular segments to form a tubular string and running the tubular string into a borehole. The method comprises the step of inserting a gripping apparatus into an end of a tubular segment, the gripping apparatus comprising a drive shaft, a drive motor for rotating the drive shaft, a first internally-threaded camming body threadably received on a first externally-threaded portion of the drive shaft, and a second internally-threaded camming body threadably received on a second externally-threaded portion of the drive shaft, such that the first and the second camming bodies adduct axially along the drive shaft, one toward the other, to narrow a jaw space intermediate the first and second camming bodies when the drive shaft rotates in a first direction, and to axially abduct, one away from the other, to widen the jaw space when the drive shaft rotates in the second, opposite direction, and a plurality of gripping jaws slidably engaged by the first and the second camming bodies such that the first and the second camming bodies adduct to slidably cam the gripping jaws from the jaw space radially outward away from the drive shaft when the drive shaft rotates in the first direction, and the first and second camming bodies abduct to accommodate retraction of the gripping jaws into the jaw space when the drive shaft rotates in the second, opposite direction.

The method of the present invention comprises the steps of operating the drive motor of the gripping apparatus to rotate the drive shaft such that the first and the second camming bodies of the gripping apparatus adduct to deploy the gripping jaws into gripping contact with an interior wall of the tubular segment, and then the step of operating a hoist coupled to the gripping apparatus to lift and position the gripping apparatus and the tubular segment. Alternately, the method of the present invention may comprise the steps of operating the drive motor of the gripping apparatus to rotate the drive shaft such that the first and second camming bodies of the gripping apparatus adduct to deploy the gripping jaws into gripping contact with an interior wall of the tubular segment, and then the step of operating a top drive or other torquing tool to rotate the gripping apparatus and the tubular segment to make-up a threaded tubular connection.

Further aspects, features, and advantages of the present invention will be apparent to those of ordinary skill in the art upon examining the accompanying drawings and upon reading the following disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation partial cross-section view of one embodiment of the gripping apparatus of the present invention in the retracted position and received within the bore of a tubular segment.

FIG. 2 is an elevation partial cross-section view of the embodiment of the gripping apparatus of FIG. 1 deployed to the gripping position.

FIG. 3 is an elevation partial cross-section view of an alternate embodiment of the gripping assembly of the present invention having a hollow drive shaft for receiving and cooperating with a fill-up and circulation assembly, the gripping assembly adapted for being supported by a pair of bails.

FIG. 4 is an elevation partial cross-section view of the gripping apparatus of FIG. 3 received within the bore of a tubular segment and aligned with a fill-up and circulation assembly, wherein the fill-up and circulation assembly is in a disengaged position aligned with the hollow bore of the drive shaft.

FIG. 5 is an elevation view of the gripping apparatus of FIG. 4 with the fill-up and circulation assembly inserted within the hollow bore of the drive shaft to facilitate the introduction of pressurized fluid into the bore of the tubular string.

FIG. 6 is an elevation partial cross-section view of an alternate gripping apparatus of the present invention comprising an integral gripping apparatus and fill-up and circulation assembly adapted for coupling to and being supported by pair of bails.

FIG. 6A is an enlarged elevation view of the camming bodies of FIG. 6 illustrating generally flat surfaces machined into the camming bodies for providing improved camming engagement between each of the camming bodies and the gripping jaw.

FIG. 6B is an interior elevation view of one embodiment of a gripping jaw having generally flat surfaces for mating engagement with the flat surfaces on the opposed camming bodies of FIG. 6A.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

wn in partial FIGS. 1 and 2 are elevation partial cross-section views of one embodiment of the gripping apparatus 10 of the present invention with portions of the gripping apparatus 10 and the tubular segment 90 shol cross-section. The drive shaft 51 is not shown in cross-section in FIGS. 1 and 2 to illustrate the two externally-threaded portions of the drive shaft 51.

As shown in FIGS. 1 and 2, the gripping apparatus 10 of the illustrated embodiment comprises a proximal end 11 and a distal end 19. The gripping apparatus further comprises, at the proximal end 11, a coupling 14 secured to a housing 22, and a motor 20 and a battery 21 disposed within the housing 22. The gripping apparatus 10 further comprises, at the distal end 19, a nose guide 16, e.g., tapered bullnose, for guiding the gripping apparatus 10 into the bore 92 of tubular segment 90. The embodiment of the gripping apparatus 10 shown in FIGS. 1 and 2 further comprises two generally axial cam guides 60, 62 extending between the housing 22 at the proximal end 11 and the distal end 19.

The coupling 14 on the embodiment shown in FIGS. 1 and 2 is a threaded and tapered coupling that may be used to couple the gripping apparatus 10 to a sub 12 or other member. The sub 12 may be coupled to a top drive assembly (not shown) for supporting and rotating the gripping apparatus 10 as is known in the art. Additionally or alternatively, the housing 22 may include other attachment member(s), for example, as illustrated in FIGS. 3-6, as a pair of laterally opposed lift ears 130 for suspending the gripping apparatus 10 from a pair of elongate bails 132, 134 adapted for being hung from a traveling block.

The gripping apparatus 10 of the present invention may be supported using a thread compensation assembly so that torque and rotation may be applied to the gripping apparatus 10 while accommodating movement of the gripped tubular in a direction generally along the axis of the drive shaft 51. A splined load compensation assembly, for example, utilizing an expandable bladder, cylinders or the like, may compensate for overlapping of threads during the make-up of a threaded connection by permitting extension of the overall length of the thread compensation assembly between the top drive assembly or traveling block and the gripping apparatus. For example, a splined assembly attached to and supporting the sub 12 in FIG. 2 can allow downwardly vertical movement of the gripping apparatus 10 and the internally gripped tubular segment 90 during threaded make-up of the connection between the tubular segment 90 and a tubing string (not shown) there below.

The gripping apparatus 10 illustrated in FIGS. 1 and 2 further comprises a motor 20 and battery 21 disposed within housing 22, a drive shaft 51 coupled to and extending downwardly from the motor through an opening 50 in the portion of the housing 22 disposed toward the distal end 19 of the gripping apparatus 10. The distal end 19 of the gripping apparatus 10 comprises an axle well 56 for rotatably receiving the distal end 59 of drive shaft 51 which can provide stability during powered rotation of the drive shaft 51. The drive shaft 51 can be rotatable by operation of the motor 20, and can include a first externally-threaded portion 52 of the drive shaft 51 near its proximal end 50 and a second externally-threaded portion 54 of the drive shaft 51 at a position adjacent to the first externally-threaded portion 52. The gripping apparatus 10 shown in FIGS. 1 and 2 further comprises a first internally-threaded camming body 32 threadably received onto the first externally-threaded portion 52 of drive shaft 51 and a second internally-threaded camming body 34 threadably received onto the second externally-threaded portion 54 of the drive shaft 51. Each of the first and second internally-threaded camming bodies 32, 34 may comprise sliding inserts 32A, 34A, 42A, 44A disposed at a cam angle to the axis of the drive shaft 51 onto which each of the camming bodies 32, 34 is threadably received. The thickness of the sliding inserts 32A, 34A, 42A, 44A may vary to adapt the gripping apparatus 10 to grip varying diameters of tubular segments 90.

The sliding inserts on the camming bodies 32, 34 may comprise a lubricious material adapted for low-friction sliding contact, or the inserts may include one or more channels, grooves, holes, slots or apertures (not shown) for dispensing, directing and/or retaining a lubricant to the sliding surface. The camming bodies 32, 34 may comprise generally frusto-conical portions providing sliding surfaces for engaging and displacing gripping jaws 42 and 44. Alternately, the camming bodies may comprise a camming body having a cam surface and held in place on the shaft, or positioned along the shaft, by a threaded member, such as a threaded nut. The sliding surfaces can be sloped at a cam angle of between about 0 degrees to about 90 degrees off parallel from the axis of the drive shaft 51, e.g., between about 5 and about 45 degrees off parallel from the axis of the drive shaft 51, e.g., between about 10 and about 35 degrees off parallel from the axis of the drive shaft 51 or between about 15 and about 25 degrees off parallel from the axis of the drive shaft 51. The sliding surfaces of the camming bodies 32, 34 can together form an annular jaw space of variable size intermediate the camming bodies 32, 34, and generally circumferentially around the drive shaft 51, for selectively positioning a plurality of gripping jaws 42 and 44 as described in more detail below. As will be discussed later in relation to FIGS. 6A and 6B, the sliding surfaces of the camming bodies 32, 34 may comprise one or more generally flat areas thereon for engaging generally flat areas on the gripping jaws 42 and 44. The flat areas promote greater camming surface area over the range of adduction and abduction of the camming bodies that would be unachievable with purely frusto-conical bodies.

The camming bodies 32, 34 may be generally restrained from rotation with the drive shaft 51 to ensure desired adduction or abduction to displace or retract, respectively, the gripping jaws 42 and 44. The first and second internally-threaded camming bodies 32, 34 may be mechanically restrained from rotation with the drive shaft 51 so that the threaded engagement between the first internally-threaded camming body 32 and the first externally threaded portion 52, and the threaded engagement between the second internally-threaded camming body 34 and the second externally-threaded portion 54, results in rotation of the drive shaft 51 relative to the camming bodies 32, 34 thereby producing synchronous axial movement (adduction or abduction) of the camming bodies 32, 34 along the axis of the drive shaft 51. Threads can be any style and/or pitch, as is known in the art.

In the illustrated embodiment, the direction of the mating threads on the first externally-threaded portion 52 and the first internally-threaded camming body 32 are reversed from the direction of the mating threads on the second externally-threaded portion 54 and the second internally-threaded camming body 34. As a result, axial rotation of the drive shaft 51 in a first direction results in axial adduction of the first and second internally-threaded camming bodies 32, 34, i.e., one toward the other along the drive shaft 51, and axial rotation of the drive shaft 51 in the second, opposite direction results in axial abduction of the first and second camming bodies 32, 34, i.e., one away from the other along the drive shaft 51.

The positions of the camming bodies 32, 34, one relative to the other, determines the size of the jaw space there between, and the radial position of the plurality of gripping jaws 42 and 44 that are movably received within the jaw space intermediate the sliding surfaces of the camming bodies 32, 34. FIGS. 1 and 2 show two gripping jaws 42 and 44, each having two sliding surfaces, one disposed in sliding contact with a sliding surface of the first internally-threaded camming body 32 and the other disposed in contact with a sliding surface of the second internally-threaded camming body 34.

FIG. 1 shows the camming bodies in an abducted position one relative to the other to form a generally widened jaw space. In this condition, the camming bodies 32, 34 are disposed sufficiently far apart to allow for substantial disengagement of the gripping jaws 42 and 44 from the internal wall of the tubular segment 90 by radial inward retraction of the plurality of gripping jaws 42 and 44 into the jaw space and toward the drive shaft 51. In this condition, the camming bodies 32, 34 are disposed apart to allow for fullest radial inward retraction of the plurality of gripping jaws into the jaw space toward the drive shaft 51. FIG. 2 shows the gripping apparatus of FIG. 1 actuated to a deployed position. The internally-threaded camming bodies 32, 34 are shown after being adducted, one toward to the other, e.g., to reduce the size of the jaw space intermediate the camming bodies 32, 34. FIG. 2 shows the camming bodies 32, 34 after clockwise (looking from motor 20 down drive shaft 51 toward the bullnose 56) axial rotation of the drive shaft 51, the camming bodies 32, 34 adducted to a deployed position to substantially reduce the size of the jaw space, and to slidably displace the gripping jaws 42 and 44 radially outwardly to engage and grip the interior wall of the tubular member 90.

The drive motor 14 that rotates the drive shaft 51 to adduct and abduct the camming bodies 32, 34 of the gripping assembly 10 shown in FIGS. 1 and 2 may be an electrically-powered motor with either an external electrical power source or an on-board battery 21 as shown in FIGS. 1 and 2. The motor for rotating the drive-shaft 51 may alternately comprise a hydraulically-powered motor, a pneumatically-powered motor or a mechanically-powered (manual) motor.

The internal grip applied by the gripping assembly 10 of the present invention results in a self-tightening grip; that is, the transfer of the weight of the tubular segment 90 to the gripping jaws 42 and 44 of the gripping assembly 10, or downward force against the gripping assembly 10, causes at least one of the gripping jaws 42 and 44 to be further cammed outwardly according to the cam angle of the sliding contact between the lower sliding surface of the gripping jaws 42 and 44 and the mating sliding surface of the second internally-threaded camming body 34. Also, the gripping assembly 10 of the present invention provides a balanced application of deployment forces on the gripping jaws 42 and 44 so that substantially all of the torque output from the motor that is not converted to friction along the sliding contact surfaces is transferred radially outwardly as engaging force on the gripping jaws 42 and 44 to grip the interior wall of the tubular member 90.

In the embodiment of the gripping apparatus 10 shown in FIGS. 1 and 2, the entire apparatus is sized and configured to enable insertion of the entire gripping apparatus, including the motor 20, battery 21 and the housing 22, into the bore 92 of the tubular segment 90. However, the motor 20, battery 21 and the housing 22 may be sized and configured to remain outside the bore 92 of the tubular member 90, but still in operative engagement with the drive shaft 51 to rotate the drive shaft and thereby displace the camming bodies 32, 34 and the gripping jaws 42 and 44 to engage or release the internal wall of the tubular segment 90.

The camming bodies 32 and 34 may each further comprise one or more elongate apertures extending through the body on a path generally parallel to the axis of the drive shaft 51. Apertures in each of the camming bodies 32 and 34 may receive cam guides 60 and 62, respectively, to rotatably secure the camming bodies one to the other, and to prevent rotation of the camming bodies 32 and 34 with the drive shaft 51 while slidably permitting each camming body to be displaced along the guide rods in response to rotation of the threaded drive shaft 51. Alternately, as is discussed below in relation to FIGS. 6A and 6B, the mating flat areas on the camming bodies 32 and 34 and the gripping jaws 42 and 44 described above for increasing the camming surface area may also be used to rotatably secure the gripping jaws and the drive shaft in position relative to the camming bodies, and thereby eliminate the need for guide rods or apertures to prevent unwanted rotation of the camming bodies with the drive shaft.

Each gripping jaw 42 and 44 may have a treated, coated or machined surface to provide positive gripping of the internal wall of the tubular segment 90 with minimal inelastic deformation or marking or include a gripping jaw insert 45, which can have a treated, coated or machined surface to provide positive gripping of the internal wall of the tubular segment 90 with minimal inelastic deformation or marking.

A gripping apparatus 10 may also comprise a biasing member (not shown) for biasing the gripping jaws 42 and 44 radially inwardly toward the retracted and disengaged position when the drive shaft 51 is counter-rotated for releasing the tubular segment 90. The biasing features may comprise spring(s) or other elastic members that engage and bias each gripping jaw 42 and 44. For example, but not by way of limitation, one or more elastic members, each having a first end and a second end, such as elastic bands or straps or a coil spring, may be secured at the first end to gripping jaw 42 and at a second end to the other gripping jaw 44 to bias the gripping jaws 42, 44 one toward the other. Elastic deformation of the elastic member allows the gripping jaws to be cammed radially outwardly one from the other by adduction of the camming bodies 32, 34 to engage and grip the internal wall of the tubular segment 90. Subsequently, abduction of the camming bodies 32, 34 one away from the other permits the elastic members to exert a restoring force on the gripping jaws 42, 44 and to thereby restore the gripping jaws 42, 44 to their original positions.

An alternate embodiment of a gripping apparatus 100 is illustrated in FIGS. 3-5. FIG. 3 is an elevation partial cross-section view of an alternate embodiment of the gripping assembly 100 of the present invention having a hollow drive shaft 151 for sealably receiving a fill-up and circulation tool within its bore 152. A gripping assembly 100 can be adapted for support by a pair of bails 132, 134, e.g., bails suspended and extending downwardly from a traveling block (not shown in FIG. 3) on a rig. The alternate embodiment of the gripping apparatus 100 depicted also comprises a hollow drive shaft 151 having a bore 152, two externally-threaded and oppositely-threaded portions 101, 102, a first and a second internally-threaded camming bodies 103, 104 threadably received on the first and second externally-threaded portions of the drive shaft 151 for adducting and abducting movement one relative to the other, depending on the direction of rotation of the drive shaft 151, and a plurality of gripping jaws 110 deployable radially outwardly from the drive shaft 151 by adduction of the camming bodies 103, 104. However, the embodiment illustrated in FIGS. 3-5 comprises a circumferential motor that powers the rotation of the drive shaft 151 by rotation of an open-ended sleeve 153 that couples to and rotates the drive shaft 151 leaving unobstructed axial access to the axial bore 152 in the hollow drive shaft 151. The bore 152 of the drive shaft 151 can be adapted for sealably receiving and cooperating with a fill-up and circulation assembly (see FIGS. 4 and 5) for providing pressurized fluid to the bore 119 of the tubular segment 118 gripped by the gripping apparatus 100.

The hollow drive shaft 151 can have an externally-splined portion 49 for mating rotational engagement with an internally-splined sleeve 48 that is the power output element for the motor 112. This configuration can permit sliding engagement between the externally-splined portion 49 on the drive shaft 151 and the internally-splined sleeve 48 of the motor 112. The splined coupling formed by the externally-splined portion 49 of the drive shaft 151 and the internally-splined sleeve 48 of the motor 112 may provide for axial compensation, e.g., during make-up of threaded connections between a tubular segment and a tubular string to which the segment is joined. Rotation of the camming bodies 103, 104 relative to the drive shaft 151 may be prevented using cam guides like those described above, or using flat camming surfaces like those described below in relation to FIGS. 6A and 6B.

FIG. 4 is an elevation view of the gripping apparatus 100 of FIG. 3 received within the bore 119 of a tubular segment 118. The bore 152 of the gripping apparatus 100 depicted is generally vertically aligned with a fill-up and circulation assembly 156, e.g., wherein the fill-up and circulation assembly 156 is in a disengaged position above the bore 152 of the drive shaft 151 of the gripping assembly 100. The fill-up and circulation apparatus 156, in one embodiment, comprises an elongate body 142 having a proximal end 157 pivotally coupled to a pivot arm 144 that is sealably coupled to a source of pressurized fluid (not shown), a distal end 155 coupled to a nozzle 154 for directing fluid flow from the pivot arm 144 and the internal bore of the fill-up and circulation apparatus 156 that extends through the body 142 of the fill-up and circulation tool 156 from near the proximal end 157 to the distal end 155 for delivering fluid introduced from the source of pressurized fluid through the pivot arm 144. The fill-up and circulation tool 156 can further comprise a circumferential external elastomeric seal 146 disposed between the proximal end 157 and the distal end 155 of the fill-up and circulation assembly for sealably engaging the interior wall 151A of the bore 152 of the drive shaft 151.

FIG. 5 is an elevation view of the apparatus of FIG. 4 with the fill-up and circulation assembly 156 lowered and sealably received within the bore 152 of the drive shaft 151, e.g., to enable pressurized fluid to be introduced through the fill-up and circulation assembly 156 into the bore 152 of the drive shaft and into the bore 119 of the tubing string 118 for circulating the well. Fluid introduced through the pivot arm 144 of the fill-up and assembly 156 can flow through the bore of the body 142, through the nozzle 154 and into the bore 119 of the tubular segment 118 gripped by the gripping apparatus 100. An elastomeric seal 146 can prevent pressurized fluid introduced through the fill-up and circulation assembly 156 from being discharged to the atmosphere and/or forces the introduced fluid down the bore 119 of the tubular string 118.

FIG. 6 is an elevation cross-section view of another embodiment of the gripping apparatus of the present invention comprising an integral gripping apparatus and fill-up and circulation assembly 200, e.g., adapted for coupling to and being supported by a traveling block and a pair of bails (not shown). Gripping apparatus 200 is similar to the gripping apparatus 100 of FIGS. 3-5 except that the gripping apparatus 200 of FIG. 6 comprises an upper adapter 202 above the motor housing 204 for pivotably coupling a fluid or cement delivery pivot arm 205 directly to the gripping tool 200. The embodiment shown in FIG. 6 also comprises a fill-up and circulation assembly 206 extending downwardly from the bottom of the gripping assembly portion 201 and receiving fluid from the hollow drive shaft 208, and an isolation joint 210, such as a ball and socket joint, for supportably coupling the fill-up and circulation assembly portion 203 to the bottom of the gripping assembly portion 201, thus permitting the fill-up and circulation assembly portion 201 to remain stationary while the gripping tool 200 is operated for gripping or releasing the interior wall 212 of the tubular segment 214.

The fill-up and circulation assembly portion 203 shown in FIG. 6 is a tool of the type described above which comprises a sealing element 216, a guide ring 218, fluid nozzle 220 and an optional extension sub assembly 222 which may be used to extend the fill-up and circulation assembly portion to a longer length.

If cementing operations are desired, the nozzle 220 disposed may be replaced with a cement wiper plug assembly, e.g., as described in U.S. Pat. No. 6,431,626. A wiper plug launcher assembly, e.g., of the type described in that patent, may be disposed to selectively receive a launching member, such as a ball or a dart, into the bore of the drive shaft 208 of the gripping apparatus 200 to selectively launch cement wiper plugs into the bore of the tubular string 206 to manage placement of cement in the borehole/casing annulus. Introduction of launching members may require the replacement of the upper adapter 202 with a cementing head or launching assembly, and/or replacing the fill-up and circulation assembly 203 with, e.g., a wiper plug assembly which may includes a pair of detachable cement wiper plugs. In such an arrangement, a launching member, such as a ball or dart, may be released from the cementing head to be received in a targeted cement wiper plug to launch the targeted wiper plug to isolate the fluid in the bore of the tubular string 203 ahead of the wiper plug from the cement slurry being pumped in behind the wiper plug. As the predetermined volume of cement slurry is being pumped into the tubular string, the first-launched wiper plug can lead the volume of cement slurry down the bore of the tubular string towards the end. Once all of the predetermined volume of cement slurry is pumped into the bore of the tubular string, a second launching member can be introduced to launch the second cement wiper plug into the bore of the tubular string, e.g., to isolate the trailing end of the volume of cement slurry from the fluid used to displace the trailing cement wiper plug and the cement slurry ahead of it down the bore of the tubular string. This system may be used to provide precise placement of uncontaminated cement slurry into the annulus.

The combination gripping and fill-up and circulation assemblies 200 of the present invention can include a passageway extending through the drive shaft 208 for delivering mud, fluid or cement into the tubular drive shaft 208, a drive motor 209 for engaging drive shaft 208 for rotating the drive shaft 208, a stop pad 226 on the bottom of the motor housing 204 for engaging the end of the tubular 214 when the tool 200 is fully inserted, and a pair of opposing ears 230 extending laterally from the housing 204 for pivotably attaching the combination gripping and fill-up and circulation assemblies 200 for being suspended from a pair of bails, or any combination thereof. The bails can extend, for example, from a conventional traveling block and hook assembly which is preferably mounted on rails inside a rig mast or derrick structure so as to accommodate any reactive torque applied by the tool drive motor.

FIG. 6A is an enlarged elevation cross-section view of the camming bodies 207 and 209 of FIG. 6 illustrating generally flat surfaces machined into the generally opposed camming bodies for providing improved camming engagement between each of the camming bodies 207 and 209 and the gripping jaw 224. The flat surfaces provide greater camming surface area that is maintained over a greater range of motion as the camming bodies slide against the gripping jaw. FIG. 6B is an interior elevation view of one embodiment of a gripping jaw 224 having generally flat surfaces 225A, 225B, 226A and 226B for mating engagement with the flat surfaces 215A, 215B, 216A and 216B on the opposed camming bodies of FIG. 6A. It should be noted that not all of the flat surfaces on any cam engage all of the flat surfaces on any gripping jaw.

An embodiment of the opposed camming bodies and one gripping jaw for cooperating with and being deployed by adduction of the camming bodies is illustrated in FIGS. 6A and 6B. As shown in FIG. 6A, two flat surfaces 215A (to the right) and 215B (to the left) are disposed in a generally side-by-side arrangement on the first camming body 207. Similarly, two flat surfaces 216A (right) and 216B (left) are disposed in a generally side-by-side arrangement on the second camming body 209. The first camming body 207 and the second camming body 209 each comprise other similar pairs of side-by-side flat surfaces that cannot be seen in the cross-section view of FIG. 6A. The flat surface 225A on the top, left interior portion of the gripping jaw 224 shown in FIG. 6B may be positioned, within an assembled internally gripping tool, such as the one illustrated in FIG. 6, to slidably engage the flat surface 215A on the right side of the exposed portion of the first camming body 207 in FIG. 6A. The flat surface 225B on the top, right interior portion of the gripping jaw 224 shown in FIG. 6B may be positioned, within an assembled internally gripping tool, such as the one illustrated in FIG. 6, to slidably engage the flat surface 215B on the left side of the exposed portion of the first camming body 207 in FIG. 6A. Similarly, flat surface 226A on the bottom, left interior portion of the gripping jaw 224 shown in FIG. 6B may be positioned, within an assembled internally gripping tool, such as the one illustrated in FIG. 6, to slidably engage the flat surface 216A on the right side of the exposed portion of the second camming body 209 in FIG. 6A. The flat surface 226B on the bottom, right interior portion of the gripping jaw 224 shown in FIG. 6B may be positioned, within an assembled internally gripping tool, such as the one illustrated in FIG. 6, to slidably engage the flat surface 216B on the left side of the exposed portion of the second camming body 209 in FIG. 6A.

The gripping tool of the present invention may also comprise an externally gripping tool. An alternate embodiment comprises an externally gripping apparatus having a first generally ring-shaped camming body with a sloped interior cam surface and a second, opposed generally ring-shaped camming body with an oppositely sloped interior cam surface, and a plurality of angularly distributed and radially inwardly deployable gripping jaws intermediate the first and second camming bodies. The tubular segment is receivable within a bore formed by the aligned camming bodies and the gripping jaws intermediate the camming bodies. The oppositely-sloped camming surfaces on the interior of the ring-shaped camming bodies together form a variable jaw space there between, and the jaw space is reduced upon adduction of the camming bodies, one toward the other, to reduce the jaw space and to slidably displace the gripping jaws radially inwardly to engage and grip the external wall of a tubular segment received within the bore. The tubular segment is releasable from the apparatus by abducting the camming bodies, one away from the other, to increase the size of the jaw space to accommodate the radially outwardly retraction of the gripping jaws so that more of the gripping jaws are received into the jaw space formed between the oppositely-sloped interior surfaces of the camming bodies.

The adduction and abduction of the camming bodies may be implemented in one embodiment by forming threads on the radially outwardly exterior of the first camming body, and forming oppositely-pitched threads on the radially outwardly exterior of the second camming body, and then by disposing the camming bodies, along with the gripping jaws intermediate the camming bodies, within the bore of an internally threaded sleeve having a first internally threaded portion for threadably receiving the first camming body and a second internally and oppositely threaded portion for threadably receiving the second camming body. In a manner much like the drive shaft of the internally threaded embodiment described above, rotation of the internally threaded sleeve in a first direction, relative to the two opposing camming bodies received therein, causes the first camming body to move downwardly toward the second camming body and the jaw space, and the second camming body to move upwardly toward the first camming body and the jaw space, to reduce the jaw space and slidably cam and deploy the gripping jaws radially inwardly to engage and grip the external wall of the tubular segment received within the bore.

In an alternate embodiment, the adduction and the abduction of the camming bodies may be implemented using a plurality of externally-threaded drive shafts that are received within internally threaded and aligned apertures through the camming bodies that are generally parallel to, but offset from, the bore. For example, but not by way of limitation, the first camming body may comprise three generally parallel apertures there through that are generally parallel to an axis of the bore of the generally ring-shaped camming body into which the tubular segment is receivable. The apertures of the first camming body are alignable with a similar set of apertures in the second, opposing generally ring-shaped camming body when the two camming bodies are aligned and positioned within the gripping apparatus for receiving a tubular segment therein. Each of the generally parallel apertures of the first camming body are threaded oppositely the threads in the aligned aperture of the second, opposite camming body. An externally threaded drive shaft is received within each pair of aligned apertures so that simultaneous rotation of the three drive shafts in a first direction within the three pairs of aligned apertures results in adduction of the camming bodies, one toward the other, and rotation of the three drive shafts in the second, opposite direction causes the camming bodies to abduct, one away from the other.

Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the appended claims.

The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention. 

1. An internally gripping apparatus to releasably grip a tubular member, comprising: a drive shaft having a first portion and a second portion, each with external threads, the first portion oppositely threaded from the second portion; a first camming body and a second camming body, separated one from the other by a variable jaw space, the first camming body threadably engaging the first portion of the drive shaft and the second camming body engaging the second threaded portion of the drive shaft, each camming body having at least one sliding contact portion that is positionable by rotation of the drive shaft within the camming body; and a plurality of dual-tapered gripping jaws disposed at least partially within the variable jaw space between the first camming body and second camming body, each dual-tapered gripping jaw having a tapered contact surface disposed in sliding engagement with the contact surface of the first camming body and a second contact surface in sliding engagement with the contact surface of the second camming body; wherein axial rotation of the drive shaft in a first direction simultaneously adducts the first camming body and the second camming body, one toward the other, to slidably displace the dual-tapered gripping jaws radially outwardly from the variable jaw space therebetween and to a gripping position, and wherein axial rotation of the drive shaft in the second, opposite direction abducts the first camming body and second camming body, one from the other, to increase the variable jaw space therebetween to facilitate retraction of the dual-tapered gripping jaws radially inwardly from a gripping position and toward the drive shaft.
 2. A gripping assembly to internally grip a tubular member comprising: a first axial cam and a second axial cam, in a variably spaced-apart relationship, each having a bore to threadably engage a camshaft, and together having opposed sliding contact surfaces forming a variable jaw space there between; and a plurality of gripping jaws, each received at least partially within the variable jaw space, each gripping jaw having generally convergent sliding contact surfaces, one to engage the second axial cam and one to engage the first axial cam, and a radially outwardly disposed gripping surface; wherein axial rotation of the camshaft adducts the first cam and the second cam, one towards the other, to reduce the variable jaw space and to slidably displace the gripping jaws radially outwardly from the jaw space.
 3. A tool to grip a tubular member comprising: a drive shaft having a first threaded portion and a second threaded portion; a drive motor operatively coupled to rotate the drive shaft; a first camming body threadably received on the first threaded portion of the drive shaft; a second camming body threadably received on the second threaded portion of the drive shaft; and a plurality of gripping jaws slidably deployed by adduction of the first camming body and the second camming body toward a gripping position when the drive motor rotates the drive shaft in a first direction.
 4. The tool of claim 3, wherein the gripping jaws retract from the gripping position when the drive motor rotates the drive shaft in the second, opposite direction;
 5. The tool of claim 3 wherein: the first camming body has an exterior generally frusto-conical surface that diverges outwardly from the drive shaft in a first longitudinal direction; and the second camming body has an exterior generally frusto-conical surface that diverges outwardly from the drive shaft in a second longitudinal direction opposite the first longitudinal direction.
 6. The tool of claim 3 further comprising at least one guide member rotatably securing the first camming body to the second camming body such that the first camming body and the second camming body are movable longitudinally one relative to the other, but the guide member prevents the first camming body and the second camming body from rotating one relative to the other.
 7. The tool of claim 3 further comprising a motor coupled to rotate the drive shaft.
 8. The tool of claim 3 further comprising a pair of bail attachment ears.
 9. The tool of claim 3 wherein the drive shaft has a bore to provide a fluid passageway extending longitudinally therethrough to allow a fluid to be delivered into the bore of a tubular member gripped by the tool.
 10. The tool of claim 9 further comprising a valve coupled to the bore of the drive shaft.
 11. The tool of claim 9 wherein the tool includes a sealing element to sealing against said interior wall of a tubular member gripped by the tool.
 12. The tool of claim 9 further comprising a nozzle coupled to the bore of the drive shaft to extend the fluid passage.
 13. An apparatus to grip a tubular member comprising: a gripping assembly including a rotatable drive shaft having a first threaded portion, a second threaded portion with the threads of the first threaded portion pitched oppositely from the threads of the second threaded portion, a fluid passageway extending longitudinally through at least a portion of the drive shaft, at least one drive motor to rotate the drive shaft, a first threaded camming body threadably received on the first threaded portion of the drive shaft, and a second threaded camming body threadably received on the second threaded portion of the drive shaft, wherein the first camming body and the second camming body are positionable along the drive shaft by rotation of the drive shaft within the first camming body and the second camming body to adduct the first camming body and the second camming body one toward the other upon rotation of the drive shaft in a first direction to reduce a variable annular space therebetween and to thereby cam a plurality of gripping jaws radially outwardly against the interior wall of a tubular member in which the gripping assembly is inserted.
 14. The apparatus of claim 13 further comprising: a pair of ears to receive bail arms from which the apparatus is suspended.
 15. The apparatus of claim 13 further comprising one or more generally flat surfaces on the camming bodies to slidably engage one or more generally flat surfaces on the gripping jaws.
 16. The apparatus of claim 13 further comprising a seal disposed on the exterior of the apparatus to seal with the interior wall of a tubular segment.
 17. The apparatus of claim 13 further comprising a valve in communication with the fluid passageway, the valve having an open position to permit fluid flow through the passageway and a closed position to substantially prevent flow through the passageway.
 18. A method of connecting a tubular segment to a tubular string comprising the steps of: inserting a gripping tool into an end of a tubular segment, said gripping tool comprising a drive shaft having a first threaded portion and a second threaded portion, the second threaded portion having threads that are pitched oppositely from the threads of the first threaded portion, at least one drive motor to rotate the drive shaft, a first camming body threadably received on the first threaded portion of the drive shaft, a second camming body threadably received on the second threaded portion of the drive shaft, wherein the first camming body and the second camming body are positionable along the first threaded portion and the second threaded portion, respectively, of the drive shaft to adduct one toward other when the drive shaft is rotated in a first direction, and to abduct one from the other when the drive shaft is rotated in the second, opposite direction, and a plurality of gripping jaws cammed by said first camming body and said second camming body when the drive shaft is rotated in the first direction to deploy the gripping jaws radially outwardly from the drive shaft; and operating the drive motor to rotate the drive shaft in the first direction to engage the gripping jaws with the interior wall of the tubular segment.
 19. The apparatus of claim 18 further comprising the step of: rotating the gripping tool using a top drive quill to make-up a threaded connection between the tubular segment and a tubular string.
 20. The apparatus of claim 1 wherein the drive shaft comprises a bore through the apparatus.
 21. The gripping assembly of claim 2 wherein the drive shaft comprises a bore through the apparatus.
 22. The apparatus of claim 20 wherein the apparatus comprises an external seal to seal with the interior wall of a tubular segment.
 23. The gripping assembly of claim 21 wherein the gripping assembly is coupled to a seal to sealably engage with the interior wall of a tubular segment to be gripped using the gripping assembly.
 24. The gripping assembly of claim 2 wherein the camshaft has a bore to permit fluid flow through the camshaft.
 25. The gripping assembly of claim 24 further comprising a seal to engage the interior wall of a tubular segment gripped by the gripping assembly. 